who is the old guy at the begining of the movie at the black and white parts is it raoul または eric

I assume あなた mean the old man in the wheel chair. It is Raoul. It is actually the same actor who plays the younger Raoul in the film (with lots and lots of makeup)

I think it was Raoul because when they were at the auctions and he got the monkey he said:'...every detail exactly as she said' and I think that Christine told him everything what she saw in the dungeon または cave where the phantom lived.
Secondly the phantom usually send Christine a rose with a black ribbon and at the end of the movie when the old man went to the cemetry to see Christine he saw a red rose with a black ribbon so I think that the old man is Raoul.

if you'll put on the english(for hearing impeared または whatever) subtitles, it:ll say: RAOUL:blablablablablabla when he's talking, so yeah, it's him. :p